The present invention is concerned with a planting tube for plants, at whose bottom end there is a blade consisting of jaws, which said jaws can be opened by depressing a foot lever. A planting tube is used in particular in forest planting when ball plants are planted.
From the Finnish Pat. No. 50,033 (equivalent, e.g., of the U.S. Pat. No. 3,749,034) a planting device for plants is known which comprises a frame tube, at its bottom end a stationary jaw, and a pivoting jaw mounted in contact with the stationary jaw, the said jaws constituting a blade to be pressed into the ground. The pivoting jaw is connected with a foot lever, by whose depression the blade pushed into the ground is opened and a planting recess is formed in the ground. The plant to be planted is dropped through the open mouth of the tube into the planting pit. The planting device is further provided with a catch and discharge device for keeping the pivoting jaw open and for its releasing back to the closed position. The catch and discharge device includes a hook member operating by means of the force of a spring, which said hook member locks the opened pivoting jaw in the open position and which can be released by the intermediate of a discharge rod connected with the hook member and extending to the top portion of the tube.
The hook member is mounted on the tube, and it is pressed against the pivoting jaw by a spiral spring fitted around the journalling pin. The hook member is provided with a notch, and the pivoting jaw with a counter-piece for the said notch. Moreover, the planting tube includes a spring, by means of which the pivoting jaw is closed. The spring is a draw spring fitted between the foot lever and the tube.
A drawback of this device is the relatively high force required for releasing the pivoting jaw, owing to the friction in the catch mechanism. A modification of the tube described above is also known, in which the hook member is mounted on the pivoting jaw and the counter-piece for the notch on the hook member is placed in the top portion of the tube. By in this way placing a part of the catch and discharge device in the top portion of the tube, it has been possible to reduce the damage caused by brushwood and rocks on the mechanism. This device, however, also involves the drawback of the high force required for releasing the pivoting jaw.